Slipjointed knockdown cabinet

ABSTRACT

A NUMBER OF PERCUT PANELS ARE ASSEMBLED INTO A COMPLETED CABINET WITHOUT REQUIRING ANY GLUE, FASTENERS, CLAMPS, OTHER STRENGTHENERS, OR SPECIAL TOOLS. INTERLOCKING TONGUE AND GROOVE SLOTS IN THE PANELS ENABLE THEM TO SLIDE TOGETHER WITH A NEARLY PERFECT FIT TO FORM A CABINET.

July 4, 1972 w rr ET AL 3,674,328

SLIPJ'OINTED KNOCKDOWN CABINET Filed D80. 10, 1970 INVENTORS KENNETH N. WHITE HAROLD E4 MEYER ATTORNEYS United States Patent U.S. Cl. 312-263 5 Claims ABSTRACT OF THE DISCLOSURE A number of precut panels are assembled into a completed cabinet Without requiring any glue, fasteners, clamps, other strengtheners, or special tools. Interlocking tongue and groove slots in the panels enable them to slide together with a nearly perfect fit to form a cabinet.

This invention relates to cabinets, in general, and to methods of making, shipping, assembling and installing knockdown cabinets which are ready for quick and easy assembly with little or no special tools; and no glue, fasteners, or the like are required at the site of installation.

Wooden cabinets are widely used in modern homes, ofiices, work, and other areas.

Exemplary of these cabinets is a bathroom vanity wherein wooden panels are assembled to make a box-like structure suitable for receiving a plastic, marble, or tile top. Usually there is a toe space at the floor in the front of the vanity. Swinging doors and sliding drawers are mounted in the cabinet. Sometimes sinks are sunk into the top of the cabinets.

These cabinets are generally made in a factory where there are precision tools, jigs, and fixtures for making a perfectly squared structure with a precision fit between each part. After making the cabinet panels, the manufacturer is required to elect the best mode of shipment. On one hand, the panels may be fastened together in a factory and shipped as a unit. The assembled cabinet will thus have a substantial volume and most of the shipping box is filled with dead air space. On the other hand, if the cabinet is shipped in a knockdown condition, it must be assembled on site, and that had been to difficult to accomplish with a quality cabinet.

Although knockdown cabinets are, per so, very old and well known, a considerable skill is required to assemble them perfectly. For example, consider the problems of assembling a simple cubical box having six precut side panels. If all of the panels are out perfectly and fitted together perfectly during assembly, there are no problems. However, if the first two panels are slightly off square or are fastened together with a minor misfit, none of the remaining four panels will fit together either. Each panel is off by an amount which reflects not only the original misfit, but also any other cumulative errors which occurs during the assembly operation. A result is that six precut panels generally come together into a lose and poorly aligned cube.

Assume that the original panels are perfect when made, they may become slightly warped or else there may be mismatched selections from opposite maximum or minimum extremities of the allowable manufacturing tolerances. Perhaps human error may occur during any manufacturing step performed on the panels or during the assembly thereof. Clearly, the cumulative assembly errors are magnified sharply by these and other non-predictable events.

Finally, visualize how any moving parts must fit together and into the assembly. Drawers should slide freely. Doors should swing or slide smoothly. However, if the panels are skewed or warped, or if other assembly faults enter, the mechanical action becomes impossible, impractical, or intolerable.

In an effort to counteract these and similar problems of on site assembly of knockdown cabinets, brute force efforts sometime have been undertaken to make knockdown cabinets fit together in a better manner. Thus, the prior art has tended to reek with instruction on how to use nails, screws, glue, wedges, clamps, and the like to force panels to come together against their will. The trouble is that the brute force method only complicates matters. Glue joints pop apart or panels split at a later date. If clamps pull the first assembled, mismatched panel into a perfect fit, and then they are rigidly attached by glue and screws, the later assembled panels are certain to be mismatched. Again, minor tolerance errors accumulate into a still further mismatch.

On the other hand, if the panels are not rigidly matched, there is a give and the cabinet parts tend to wobble with respect to each other. As the assembled cabinets are pushed, shoved, set upon, and as drawers or doors are pulled or twisted, the loseness of nails, clamps or other fasteners increases and the cabinet ultimately falls apart. Therefore, knockdown cabinets have tended to be restricted to either low cost, do-it-yourself products or to products which are assembled by skilled mechanics in a factory-like atmosphere.

For these and other reasons, the quality products continues to be complete cabinets fully assembled in a factory and shipped in a large box filled mostly by empty air. Moreover, the surfaces of these cabinets must be protected by cardboard boxes or the like. In view of the size of these boxes, they must be very expensive and strong, with substantial padding and reinforcing.

Accordingly, an object of this invention is to provide new and improved knockdown cabinet construction. Here, an object is to provide a kit of preshaped panels which easily and automatically distribute manufacturing tolerance diiferences without introducing any substantial or cumulative assembly errors. In particular, an object is to enable a completely loose joint assembly with the precision heretofore available only in factories or from skilled mechanics. In this connection, an object is to provide a cabinet with enough give to enable it to be aligned after complete assembly and yet will not wobble, become loose, or fall apart at a later date.

Another object of the invention is to provide new and novel methods and procedures for the assembly of knockdown cabinet kits. More particularly, an object is to provide methods which do not require special purpose tools or substantial investment in capital. equipment.

Yet another object is to provide knockdown cabinets which are quality furniture.

In keeping with an aspect of this invention, these and other objects are accomplished by new and novel panels having mating slip joints for on site assembly. More particularly, each panel has a number of tongue and groove keyway slots or dovetailing joints cut therein at precise locations. The locations of these slots and joints may be made with a precision heretofore available only with factory tooling. The tongue part of the joints on one panel fit into the slots or grooves on another panel with a precision which gives a desired degree of tightness in the finally assembled cabinet. Still, there is a looseness such that, if the cabinet is not perfectly square, or it wobbles, local pressure may be applied to a selected joint and the cabinet panels slip tightly to square it and stabilize it.

The nature of a preferred embodiment of the invention for accomplishing the above and other objects may be understood best from a study of the attached drawings, in which:

FIG. 1 is a perspective exploded view of a partly as- 3 sembled cabinet incorporating the principles of the invention;

FIG. 2 is a plan view of a shipping container illustrating the cabinet as shipped in a knockdown condition;

FIG. 3 shows a first step in the assembly of the cabinet;

FIG. 4 is an adjusting step wherein the assembled cabinet is squared; and

FIG. 5 is a completely assembled vanity or cabinet made by the inventive process.

An exploded view of a partly assembled cabinet, constructed according to the teachings of this invention, is seen in FIG. 1. The principal parts of this cabinet are a pair of precut stringer or cross brace parts 50, 51, a pair of side panels 52, 53 which are mirror images of each other, and a bottom panel 54. Door mounting means 55a, 55b, and a top brace 56 are provided to complete the assembly, but they are not necessarily a required part of the basic cabinet. Doors 57, 58 (FIG. 5) may thus be hung on the upright parts 55a, 55b. And drawer 59 may also be included, as desired. A back panel (not shown) may be attached to the back of the finished cabinet. The panels may be prefinished or unfinished depending upon the buyers needs.

Each of the braces or panels is precut with factory precision to provide a perfect fit when the assembly is completed. A number of key slots having a flared cross section are precisely cut into the edges of the panels at selected locations, as shown at 60-66, by way of example. Mating slip joints 70-76, with a complimentary flare, are cut into the edge of panels at precisely located positions. Thus, the slip joint 71, for example, slides in directions A, B (FIG. 3) into the slot 61 as a first step taken during assembly of the cabinet. However, the part 71 does not thereafter pull out of the slot 61 in the direction C. For convenience of expression, this arrangement is hereinafter called a dovetail slip joint.

Means are provided for strengthening the edge of a panel adjacent a keyway or slot. More particularly, at some locations the key slot may be near an edge of a panel, as slot 60 is here shown near the front edge of the panel 52. This leaves a land area between the panel edge and the slot 60, with the land area having a thickness T. If made too thin, the land area might break off under abusive wear. If made too thick, the land area would cause the doors to be set too far back into the cabinet. Therefore, the desire is to make this land area as thick as possible without causing an unattractive appearance.

According to the invention, these conflicting demands are accomplished by asymmetrically forming the mating tongue. Thus, as shown at 55b, in FIG. 1, the area C1 at the rear edge of the tongue is relatively deep. Therefore, the thickness T is maximized and yet the door panels may set flush with the front of the cabinet A.

It should be noted that the key slots are positioned to give the cabinet great strength and rigidity. Thus, for example, the fiared grooves formed by slots 62, 66 are horizontally opposed to receive the floor or bottom 54 of the cabinet. The slots 61, 63, 65 (and another which is not seen in the drawings) form vertically opposed slots on diagonally opposed corners of the cabinet to receive the cross bracing 50, 51. The floor 54 and cross bracing 50, 51 are squared to enable the cabinet to fit together into a tight and integrated unit. The cross bracing 56 is here shown as fitting into the upright standards 55a, 55b.

The preferred embodiment is made entirely from wood. No other assembly or mounting aids are required, such as nailer strips, glue, or brackets for interconnecting the cabinet parts. Nevertheless, the invention is broad enough to cover suitable modifications which might readily occur to those who are skilled in the art. For example, either slots 60-66 or the joints 70-76 (or both) might be metal or plastic tracks or liners attached to the wooden panels. Furthermore, any suitable edge banding might be provided for strength or beauty.

As will become more apparent, the cabinet is shipped in a knocked-down condition (FIG. 2) with all panels 50-56 separated from each other and packed in a suitable box 80. The box has a minimum amount of waste space. Because of its smaller and more compact size, it does not have to be as strong. Only a minimum number of pads are required to prevent rattling, as at 81. The knockdown kit includes:

(1) Front and back cross bracing 50, 51, 56,

(2) A bottom panel 54,

(3) Two mirror image side panels 52, 53, and

(4) Other optional parts such as uprights 55, doors, shelves, and drawers, included at the buyers option.

The person receiving this kit puts the panels together by fitting each of the dovetail joints into a mating slot. There is no need to use special purpose tools or hardware to draw the panels together in a perfect fit. The clamping-like pressures applied between panels occurs solely from the sliding dovetail-like joints. This pressure is sufficient to overcome inadvertent misalignments, and yet it is not great enough to injure the wood or other material forming the panel. Also, the panels remain loose so that any skewed parts may be slipped with respect to each other.

With the foregoing explanation in mind, it is thought that the nature and advantages of the invention may be understood best from a description of how to manufacture, ship, and assemble a cabinet made from precut panels. Essentially, these panels fit together to form a basic cabinet which receives a suitable top, doors, drawers, decorator panels or the like.

The first step in the assembly is to stand the two side panels facing each other. Then, ends 71, 72 of the cross bracing 50 are fitted into the slots 61, 65 and pressed down (as viewed in FIG. 4). Thereafter, the ends 75, 76 of cross brace 51 are fitted into slot 63 and another slot (not seen in FIG. 2) in panel 53, and pressed upward.

The second assembly step is to slide the dovetail tongues 73, 74 of the floor or bottom panel 54 into mating dovetail grooves 62, 66 in the side panels 52, 53. Care is taken to be sure that the cross bracing and floor or bottom panel are properly positioned.

The third step is to place the partly assembled cabinet in an upright position and to test it for squareness and stability. If any instability is found it may be corrected since the cabinet is not glued or bracketed together. Thus, for example, if the corner 83 is too low and the cabinet wobbles, a block of wood (or other material) 84 could be placed under the corner and a downward pressure is applied on opposing corners, as indicated by the arrows D, E. Since the cabinet is not glued or otherwise rigidly assembled, there is a small amount of give which levels and squares the cabinet. For convenience of expression, this small amount of give may be described as resulting from prefabricated panels which are slipjointed together after assembly.

The fourth step is to add a back panel (not shown) if desired. The manner of adding this panel is irrelevant. It could fit into rabbit grooves, for example. Or, it could be attached in any other suitable manner.

The fifth step is to attach any desired front panel. For example, the two uprights 55a, 55b may be fitted into the slots 60, 64 to provide an anchor point for attaching a door.

At this step, the cabinet is completed and ready for installation. Conventional shelf supporting hardware may be inserted into holes (not shown) for supporting a shelf or drawer slides. These holes would preferably be formed in the inside surfaces of the slide panels 52, 53. Two hinges are slipped into the T-slots 86, 87. While the hinges are not shown, they may have ears which fit over the edge of strips 55 to hold them in place. Screws may be added to hold the hinges in place, as desired.

The cabinet (FIG. 5 is now complete, and secured into a tightly formed unit. Thereafter, the cabinet may be bolted to a wall, the floor, or to another cabinet of similar construction.

Those who are skilled in the art will readily perceive how various modifications may be made without departing from the scope and spirit of the invention. Therefore, the appended claims are to be construed to cover all equivalent structures.

We claim:

1. A knockdown cabinet made from prefabricated panels slipjoined together after assembly, whereby said slipjointed panels conform to the contour of the cabinet supporting area, comprising two side panels having opposing horizontal grooves at the bottom floor of said cabinet and two opposing groves on the front vertical edges of said panels, opposing grooves on diagonally opposed corners of said side panels, a squared floor panel with opposing tongues shaped to mate with said horizontal grooves, cross bracing with opposing tongues shaped to mate with diagonally opposing grooves, and vertical posts with tongues shaped to fit into said opposed vertical edge grooves,

said tongues and grooves cooperating to form dovetail slipjoints wherein said grooves are slots which are flared at the back and narrow at the front and said tongues having flared contours which mate with and fit into the flared grooves formed by said slots, at least one of said slots being positioned near an edge of said panel and the mating tongue ends of said bracing fitting into said slots being asymmetrically formed on said bracing to provide a recessed point of support.

2. The cabinet of claim 1 wherein said dovetail slipjoints slidingly fit tightly together whereby said cabinet may be put together free of extra fastening means and yet facilitate a truing of said assembled cabinets.

3. The cabinet of claim 1 wherein said bottom floor of said cabinet is elevated upon the surface supporting said cabinet, said side panels are cut to form toe space at the bottom of the cabinet, and said cross bracing forms a vertical wall kick plate at the back of said toe space.

4. The cabinet of claim 1 and door means attached to said vertical posts.

5. The cabinet of claim 1 wherein each of said panels has a side opposite said grooves with an unbroken surface providing for flush mounting of completed cabinets.

References Cited UNITED STATES PATENTS 3,379,483 4/1968 Oldford 312--257 R 2,360,451 10/1944 Stone 312-257 R 3,360,320 12/1967 Lust 312257 R 3,525,560 8/1970 Gasner et al 312257 R JAMES T. MCCALL, Primary Examiner 

